Notre Dame players tussle with USC players during pregame warmups

LOS ANGELES -- Notre Dame's nickname is the Fighting Irish. USC's catch phrase is "Fight on!" Both sides lived up to the words before kickoff Saturday.

About 45 minutes prior to the game between the 6-5 Irish and 9-1 Trojans, players from both teams had a brief but spirited skirmish on the field. As Notre Dame's players exited the tunnel and entered the playing surface, they began jawing with the USC players who already had begun their team warmups.

Players from both sides came together in a confrontation that began as nothing more than jumping and jawing but escalated. As coaches and police officers vainly attempted to separate the rivals, a few punches appeared to be thrown and a couple of players appeared to be wrestled to the ground. It was unclear from the press box which players were involved in the punching and wrestling.

By the time the two teams were sequestered on their respective sides of the field, a gauntlet of 15 uniformed police officers stretched across the 50-yard line to keep the two teams apart. Both teams settled down quickly from there and the officers dispersed. When Notre Dame left the field jogging past the USC players with roughly 28 minutes left before kickoff, there were no incidents.

Pat Forde is a senior writer for ESPN.com. He can be reached at ESPN4D@aol.com.